I used to ride about 10 minutes of city traffic to work, and I would wear office-acceptible boots (I picked some some presentable hiking boots, they're only slightly bigger than joggers, but have excellent support), good jeans, light/high airflow padded jacket (it's hot where I live), light motocross gloves, full face helmet. I kept my helmet/jacket/gloves under my desk, and wore the rest all day.
I came off once with that gear, it had been raining lightly, no traffic, and I was on auto-pilot braking into the U-turn I did every day to get to work. I grabbed too much front brake, and low-sided it at ~10kph. Walk away from that with a slight rash on the outside of my leg (not even bleeding, and no bruises).
Now I've moved to another town, but still work at the same office a few times a week. It's now ~20 min city riding (I try to get to work before peak hour, and leave work before peak hour), ~20 min twisties (250 corners!), and ~40 min of highway. Now I wear full motocross boots, the same jeans, the same jacket, heavy duty gloves, and the same helmet. I also ride more carefully than I usually would, especially in the twisties (it's sooo tempting to scream through at warp speed) and in the city (traffic can get bad). I'm still able to keep everything under the desk, and I have a pair of shoes at work ready to put on when I arrive.
I've come off twice with that gear, once was in a section of dirt trail I take from time to time on the way home, if I'm bored by the 1+ hour trip. Left me with a hole in my jeans but no injuries (low speed crash, leg pinned under bike and knee hit a rock). The second time I hit some gravel in an intersection and high sided/was thrown over the handlebars... face-planted on the road, but was slow enough not to slide. I had an extremely painful foot for 2 days (could barely stand up, needed crutches) and some minor grazes on my legs above the knees, and a few pulled muscles all over my body.
I'm fairly happy so far, figure my gear has been adequate each time I've come off. I'm extremely cautious around other cars, and our small city "peak hour" isn't too bad, so am counting on never having an accident involving another vehicle while wearing this gear.
I've decided to go and find some kind of light weight knee protection. The knee guards I have now are overkill and too cumbersome. Haven't work out what I'll go for yet.